25-year-old Grandpa

46 years ago Kurihara Minoru (Fujiwara Tatsuya) went to the mountains to take pictures, but never returned. Fast forward to the present and he is discovered perfectly preserved in ice. He then miraculously wakes up.

The head of the Kurihara household is now Kurihara Norihiko (Takahashi Katsumi), who is Minoru's son and 52 years old. Their is also Minoru's grandson Kensuke (Daito Shunsuke) and granddaughter Mai (Kurashina Kana). Their family is set for upheaval as their grandfather (who still looks 25, but is now 71) returns to their home.

At first Minoru can't act comfortably around his family, but as Minoru gets used to the change of times, their family comes around